Remote-control and indicating system



March 16, 1954 P. CUTLER REMOTE-CONTROL AND INDICATING SYSTEM 2 Sheets-Sheet 1 Filed April 22, 1949 MODULATOR fPEdMA/C) Moll/LA OSCILLAWR f i'A f I Ffimumcy MODUL/VUR TEA/VSM/UH? INVENTOR. PH/L CU TL ER osaLLATulr [:Af

MODULA T01? March 16, 1954 P. CUTLER 2,672,603

REMOTE-CONTROL AND INDICATING SYSTEM Filed April 22, 1949 2 Sheets-Sheet 2 111 R- A-F AVC gig-Z Ff 4 I i ,195

AVC R-F AMPLIFIER RECF/VER L/M/TER DEM/M L/MITER s L 185 I86 I 19/ INVENTOR. PH/L C U TL ER Patented Mar. 16, 1954 REMOTE-CONTROL AND INDICATING SYSTEM Phil Cutler, Brooklyn, N. Y., assignor of one-half to Karl F. Ross, Bronx, N. Y.

Application April 22, 1949, Serial N 0. 89,008

4 Claims. 1

The present invention relates to remotecontrol and indicating systems in which a controlled device, for instance a switch or an indicator, is selectively actuated by means of signals transmitted over a communication path which interconnects a control point and a remote point. The term communication path includes radio links as well as metallic circuits.

An object of the present invention is to provide, in a system of the character described, means for transmitting a great diversity of signals through the intermediary of electromagnetic waves occupying only a small number of communication channels each of relatively limited band width.

Another object of my invention is to provide, in a system of this type, novel and improved means for the remote actuation of a controlled device, such as a cathode ray tube.

A further object of this invention is to provide, in a remote-control and/or indicating system, receiver means at a remote point including one or more cathode ray tubes adapted to respond quickly and faithfully to a large number of commands given by a control device at a control point. 1

The above and other objects of the invention will become apparent and the invention will be best understood from the following description of certain embodiments, reference being had to the accompanying drawing in which:

Fig. 1 is a circuit diagram showing the control station in a remote-control system according to the invention;

Fig. 2 is a circuit diagram showing the remote station associated with the control station of Fig. 1;

Fig. 3 is a circuit diagram showing a modified control station, forming part of a remoteindicating system;

Fig. 4 is a circuit diagram showing the remote station associated with the control station of Fig. 3; and

Figs. 5 and 6 are diagrams illustrating the operation of the systems of the preceding figures.

Referring now to Fig.1, there is shown a corntrol station having means for selectively actuating a large number of controlled devices provided at a remote point. In the particular example illustrated it has been assumed that it is desired to control sixteen different groups of switches, such as relays, eachgroup including eight different switches each having an on and an off position, thus making a-total of 256 distinct switching-operations. 1 V:- J

The means I provide for carrying out these different operations include a push button or circuit breaker Ill, a first selector 20 and a second selector 30. Each of the two selectors includes a slotted disk 2|, 3|, respectively, each disk being divided into sixteen segments. The first selector disk, 2 I, has its segments marked A through P; the sixteen segments of second selector disk 3| are labeled #1 On through #8 On and #1 Oif through #8 Oif. The slots 22, 32 bisect each inner segment (A-H and #1 On-#8 On) and extend into each outer segment (LP and #1 Off-#8 Off) along the line of symmetry thereof.

Each selector is further provided with an actuating member comprising a rod 23, 33 a reduced portion of which passes through one of the slots of the associated disk and carries a knob 24, 34. The arrangement of the slots in the manner just described enables the knob 24, 34 to be selectively positioned on any segment, thereby indicating the group, switch or function selected. It will be understood that rests or stops, not shown, may be provided for the purpose of more positively arresting the knob in a centered position with respect to any selected segment.

The lower extremity of each rod 23, 33 is journaled for rotation in two planes in a universal joint 25, 35, respectively. Joint 25 comprises a pin 25 supporting the rod 23 in a gimbal ring 21, the latter being rotatably mounted on brackets 28, 28 by means of studs 29, 29. Similarly, the joint 35 comprises a pin 36 supporting the rod 33 in a gimbal ring 31, this ring being pivotally held on brackets 38, 38' by means of studs 39, 39.

While it is entirely possible to make the two selectors identical, I have shown for purposes of illustration two different arrangements utilizing amplitude and frequency modulation, respectively. Rod 33 carries at its lower end a source-of light, shown here as a bulb which is equidistant from four photocells 4|, 42, 43 and 44 when the knob 34 is at the center of disk 3|. The anodes of these photocells are all connected to positive potential provided by a battery 46; the cathodes are grounded by way of respective resistors 41, 48, 49 and 50.

The cathodes of photocells 4|, 43 are connected to the grids of vacuum tubes 5|, 52 forming part of a push-pull amplifier 53. This amplifier is biased by a battery 54 and is energized from an audio frequency oscillator 55 of frequency f. The output of amplifier 53 is applied through an output transformer 56 to a frequency modulator 51 which is. also connected'to a. radio frequency oscillator 58, producing a first carrier frequency F1. The modulator 51 works into a transmitter 59 having an antenna 60.

The cathodes of the remaining photocells 42, 44 are connected to the grids of vacuum tubes GI, 62 forming part of a push-pull amplifier 63. This sl ae swbias a by shat r. 4 n i energized from tl e audio; frequency; oscillator 55. which also feeds a frequency modulator 65. The output of amplifier 63 is applied through an out; put transformer 66 to a frequency modulator N which is also connected to a ra QiQ;l;e QJle pQy.Q-r cillator 68, producing a second carrier frequency F2. Modulator 6'! also works intothe transmitter 59. The modulated carrier frequenciesvFrand F2 represent two of the five channels used in this particular system and should'be sufificienrtiyspaced from each other to make them readily separable at the receivingend.

From the foregoing description it will be understood; that thepeak" amplitude and phase 0? the modulation of -car-rierwave Fr depend on the position ofbulb 45': relative to photocells 4i, l3- whilcf the pealramplitude and phase of the modulatiomof carrier wave F2 similarlydepend on thepositionofthe bulb-relative to-the photoce lls; 4 25'. Thus,- when the knob Si isplaced its n eutral'f' position at the centerof; disk 31, bulb 45 9uidi tant from the two pairs of digerentially connected photocells and the outniii qt i mpl fiers: :31 63 it e o ero WQ AFPQDIQD..ar r the y ayr he hot l 4! use ationsoi frequency f and increasing ampliisl s r ma line. seconda n o m Si; or rrrpachl ie t e pp si e ell th s e desies ease sim arlyf ut h i la io t' 1 espect'tocthose men mesons, situation exists elative d sta ce be applied it er, ul heiim nhese rinlp a piiil i i with respect to the signal applied, to modulator 55.

In tl ie case of selector 2 0,adisp1accment: of the jlri okp 24 affets: theirequency of. two audio fret} oscillator 69, 10 having tank I circuits 'II;, 12;, respectively. Tank, circuitQ'II, comprises ei itedk iai egt wn, er we condenser, aaflwa iabl emea flh hqw rherea n @e a w qi ghavin a mo abl Core. 15 c red tg th e l ow end; o f rod: 2 3; Coil 'l tiis-pivotally elds 4%: P22 5; r ie tinerom a; head? mounted on; journalstudig Tank circuit: I2 ompr ses: a; i ed 01 8:" nd a. riab e: com denser; 8;: hav ng: a, et; f t t ona y. la e as w s e i mov b e lates: heer e n se ured s heti urnal tud 2 fw ThemSGfllators; 6 and; 10 ares preferably designed so, that ,eac I not them produces law center frequency when theknob 24 occupies the center of! disk-J11 Oscillators? 5!; 10;- work into-respective frequency-.emodulatorsu 80s 81. Modulator 80 re ceives a carrier frequencyaFe from a radio-frequencymoscillator 82. Modulator 8Ireceives a carrierfrequency F4; from a radio frequency oscillator 83. The outputs of both modulators are applied :tothe transmitter 59:

A fifth" radio frequencyoscillator 04,- operating at agfrequency-Fs; is connected to .the modulator 65 :by. way-of circuit :breaken I 01- Modulator 5i :alswworksdnto thatransmittenfls The remote station, Fig. 2, comprises a receiver 85, having an antenna 285, which works into five limiters 86, 81, 88, 89 and 90 responsive to frequencies Fl-F5, respectively. The output of each limiter is applied to a respective radio frequency discriminator, indicated at 9l95. Radio frequencydiscriminators 9 3, flfisieedapair of audio frequency discriminatorsiaiz; i; respectively.

The remote station also comprises a primary cathode ray tube I00 and a set of secondary cathode ray tubes of which only two, H0 and I20,-are-sho,wn.-. Tube I00 is the counterpart of first selector 20 (Fig. 1) and is provided with sixteen targetssuch as I 0 I-l 04 (only four shown) each connected to the cathode of a respective one ofthe secondary cathode ray tubes H0, I20 etc., thetargets being further grounded through resistors such as I05, I05. The cathode of tube I00 is connected to the negative terminal of grounded battery I01. Vertical deflecting electrodes I08, l08f of tube I0'0'a1ie' connected across the output of discriminator 97', while horizontal deflecting electrodes I09, I109; are connected across the output of discriminator 96.

Each of the secondary cathode raytubes such as H0, is provided with sixtee'n targetssuch as III-I I4; (only. four shown), the secondary tubes in their totality being the, counterpart of the second selector 30 (Fig. 1).. The output of radio frequency discriminator 9.5 f"is,ap'p'ljied, by, way of abiasing battery M5, to the. grids or. intensity control electrodes of all.secondary cathode ray tubes in parallel. The .verti'calidefi'ecting electrodes such as H6, H6" and I'll, l-Ifl of all these tubes are. connected inuparallel across. the outputof discriminator 9.1 while'tiie horizontal deflecting electrodes such as I181 I.:IBIan d H9, H9 are all connected parallel; across the output of discriminator 92 Thetargets I I l-l Mare conneet editothe posi-. tive terminal I of sgrounded: battery I 2 by way of respective". switching devices I; I 2 I-. -I 2-4, Each of these, devices comprises a'-,co ndenserx-shunted re! lay, I the relays beinggrouped; in pairs: with' me chanically interlocking armatures, as shown. Relays I2I and IZ3 may-betermedthefon relays andzrelays I22, A I 24 the .ofif relay -pi the respective pairs, there being eight such pairs-L for each secondary tube. Itwill be understood 1 that the targets of tube I00=correspond-,to respective-sec.- tions A -P of selector 20 andithatzthe eightpa'irs of relays controlled by and associated iwithreach secondary tube correspondztaithe,"units: desig: nated #1-#8 on disk'3I of; selector; 30.2

We shall assumei by of'rexample=,.that target IOI corresponds to section M on di'sk;:2'I and that the pairedrelays? I2 I I22; correspond to sections #1 Omand iflq-Off,omdisk I3-I,'.re:-. spectively. It will be understood-xthatiany rdesired-load; for examp le a motorcy m tibe: switched on and off? by relays I2I- and I22; respece tively.

In order to illustrate the operationrof =the;'.system -of--Fig s.- 1 'and'=-2-, let'lls :supposethat thQiODierator atthe control point. (Figr 1) desir'edzto turn onP-the unit it'? 'in' groupr M; Thecthree steps necessarywto-r accomplislmthissare Place knob on the field M of 'disledl; lplaceiknobftd on therfield #77 On. .of disktifl .dEPT-ESSHIIOHIBIY- tarily the knobdtr- At the remote point-' (Fig; 2) the first tstep, having resulted in certain- :adjustments-mi reactive elements incthewinput:circuits 'OfE'OSCll lators 69 and 10 whichacontrolz'ithezmodulators 80 and BI, produces oscillations in the output of R.-F. discriminators 93 and 94 which correspond to the output voltages of oscillators 09 and 10, respectively, their frequencies being characteristic of the position of the knob 24. A.-F. discriminators 96 and 91 derive from these frequencies characteristicpotentials which are applied to the horizontal deflecting electrodes I09, I09 and to the vertical deflecting electrodes I08, I08 of tube I00, respectively, thereby causing the beam of this tube to impinge upon the selected target IOI. This positioning of the beam results in a voltage drop across the resistor I05 which drives the cathode of tube IIO more negative, this drop being, however, insuflicient to overcome the bias of battery H5. The beam of the tube H0, as well as that of any other secondary tube, remains therefore suppressed.

The second step, having resulted in modifications of the gain of amplifiers 53, 63 which control the modulators 51 and 61, produces oscillations in the output of R.-F. discriminators 9I and 92 which are of constant frequency f but which vary in peak amplitude and phase in the same manner as do the output voltages of transformers 56 and 66, respectively. These oscillations are directly applied to the deflecting electrodes of all the secondary tubes but, with the beams thereof suppressed, have no effect for the time being. They tend, however, to deflect the beam of each tube across the associated targets in a direction and with an amplitude which corresponds to the vector sum of the two oscillations; each beam would, therefore, carry out a linear sweep one end of which coincides with the position of the selected target (the #7 On target in this case).

The third step, having actuated the modulator 65 to apply to the transmitter 59 the output of oscillator 84 modulated by the output of oscillator 55, produces oscillations of frequency in the output of R.-F. discriminator 95. These oscillations are in phase or in phase opposition with respect to the oscillations derived from R.-F. discriminators 9I and 92, hence the peaks of all three oscillations will coincide. The output of discriminator 95 is of constant amplitude such as to overcome the bias of battery H5, together with the voltage drop developed across the resistor I05, only at the positive peaks of the oscillations produced; thus the beam of tube I I will be triggered on only at the end of its linear sweep at which time it impinges upon the target III. The other secondary tubes, in the absence of a voltage drop across their respectivecathode resistors, will remain inoperative.

The foregoing will be better understood from Fig. in which the horizontal deflecting voltage is indicated by V11 and the vertical deflecting voltage by Vv. Only at those peaks of the resulting voltage V1 which coincide with the target I I I is the beam of tube IIO of suflicient intensity to excite any target, resulting in the operation of the associated relay I2I. (The provision of a condenser in shunt with this relay has the purpose of smoothing the intermittent current resulting from the periodic impingement of the beam upon the target.)

From Fig. 5 it will also be understood that, when the outputs of both push-pull amplifiers 53 and 63 are zero (corresponding to the neutral lators 69 and are of the center frequency f (corresponding to the neutra position of knob 24), the beam of tube I00 will likewise be cen tered. In the system illustrated, no targets are provided at the centers of any tube.

The receiver 95 is preferably provided with automatic volume control means, as indicated, which together with the limiters 86--90 will serve to make the amplitudes of the discriminator outputs and, hence, of the deflecting and grid biasing voltages substantially independent of transmission conditions. The positions of the beams will, therefore, faithfully duplicate the positions of the rods 23, 33 of selectors 20 and 30.

In the modified form of the invention shown in Figs. 3 and 4, there is provided at the control station (Fig. 3) a rod or stick I33 which may be similar to the members 23, 33 previously described. The lower end of this stick carries a photocell I4I as well as the movable core I15 of an induction coil I14. This coils forms part of a tuned circuit I12 which also includes a fixed condenser I13 and is the tank circuit of an oscillator I69.

The photocell MI is illuminated from a stationary lamp I45 and has its anode energized from a battery I46. The cathode of the cell is grounded via a resistor I41 and is also connected to the grid of an amplifier tube I5I inserted in the output circuit of oscillator I69, in series with the primary of an output transformer I56. Connected to the secondary of this transformer is a frequency modulator I51 to which carrier energy of frequency F is applied by a radio frequency oscillator I58. The modulator I51 works into a transmitter I59.

The remote station, Fig. 4, comprises a receiver I feeding a limiter I96 which in turn works into a radio frequency discriminator I9I. The discriminator I9I applies a deflecting potential directly to the horizontal deflecting electrodes 209, 209' of a cathode ray tube 200. The discriminator also feeds an amplifier-limiter I which energizes the grid of tube 200 by way of a biasing battery 2I5. The vertical deflecting electrodes 208, 208' are connected to the output of a board-band filter I91 having a sloping characteristic in the frequency range fi-J2 which is the working range of oscillator I59 (Fig. 3). The filter I91 is connected across the output of limiter I95.

In this embodiment the cathode ray tube 200 is shown provided with a fluorescent screen MI in place of the targets previously described, this screen being connected to the positive pole of a grounded battery 201. A biasing battery 2I8 is inserted between the filter I91 and the vertical deflecting electrode 208, and a similar battery 2I 9 is inserted between the discriminator I9I and the horizontal deflecting electrode 209.

The operation of the system illustrated in Figs. 3 and 4 is as follows:

Batteries 2H! and 2I9 tend to focus the beam of tube 200 upon a spot S off the screen 20I, as illustrated in Fig. 6. The deflecting voltages Vh and Vv vary in step with each other, and with the voltage applied to the grid of the tube 200 by the limiter I95, the variable frequency of these voltages corresponding to the operating frequency of oscillator I99. From Fig. 6 it will be seen that a certain minimum voltage swing V is necessary for allowing the beam to reach the screen 20I, and the limiting amplifier I95 is preferably designed so that its output will have a constant amplitude when the output of discriminator I9I is of amplitude Vho or larger. The oscillations obtained from the limiter. I 95 are used to render. thebeam visible at-theirypositive peaks only, occurring-simultaneously with; the negative peaks of deflecting-voltages, V1, and Vh at a time when the beam of the tube impinges upon the screen 20L A luminous spot S will thus be produced on the screen, its position being determined by the sum'of the-vectorsVv and Vh.

It will be understood that thervariationsin amplitude of horizontal defiectingvoltage Vs will correspond to the amplitude variations. of the output of transformer I56 (Fig. 3),. the latter resulting from the changes in the gain of amplifier i5! due to displacement of photocell MI relative to light source M5, while the amplitudes of the vertical deflecting voltage'Vv will be substantially independent of thesevariations, being strictly a function of signal frequency asdetermined by the sloping characteristic of filter. I91, the signal frequency in turn being determined by the position of movable control member H5 in the input circuit of oscillator [69. (It may be mentioned that this filter may comprise or be supplemented by a sloping amplifier having the transmission characteristic shown.) Thus it can be seen that the position of the spot S can be changed by displacing the stick I33, the latter being operable to give any desired indication on the screen L By using a fluorescent material of high persistence for the screen, a trace S" of any desired configuration may be produced;

The control station, Fig. 3; may also be provided with a switch or interrupter 99 for the purpose of discontinuing the transmission of a carrier wave after a signal has been sent out.

The invention is not limited to the specific embodiments shown and described'but is on the contrary capable of numerous modifications and adaptations which, after an understanding of the present disclosure, should be obvious to those skilled in the art. Thus the transmission of signals from the control point to the remote point may be effected by means other than a frequencymodulated carrier wave; the beam of the cathode ray tube or tubes may be used for actuation of any type of controlled devices, such as photo-electric cells, vacuum tubes, thyratrons and the like; also, the sweep-of some or all of the tubes need notbe orthogonal but may be circular, helical, spiral and so forth. It is, therefore, intended that all such variations be embraced in the scope of the appended claims unless otherwise limited.

The term remote-control system, as used in the claims, is intended to cover telemetering and other remote-indicating systems as well as remote-actuating systems.

I claim:

1. A remote-control system comprising a signal transmitter at a control point, a signal receiver at a remote point, a communication path connecting said transmitter to said receiver, oscillator means at the control point connected to said transmitter and having a variable output representing a signal Wave, selector means at the control point having a movable member connected'to said oscillator means for varying the output thereof, a. cathode ray tube at said remote point connected to said receiver and provided with beamdeflecting means and with a beam intensity control electrode, first circuit meansin said'receiver connected to said beam-deflecting means for-applying thereto an oscillation derived from the received signal wave and having a peak amplitude varying with the displacement of said movable memberat the control point, secondcircuit means .in said receiver connected tosaid control electrode for applying thereto .a control wave=of substantially constant peak amplitude in step with said oscillation, and biasing means so connected to said control electrode as substantiallyto suppress the beam of said tube except at peak portions of said control wave and, thereby, of said oscillation.

2. A remote-control system comprisinga signal transmitter at a control point, a signal receiver at a remote point, a communication path connecting said transmitter to said receiver, oscillator means at the control point connected to said transmitter and having a variable output representing a signal wave, selector means at the control point having a movable member connected to said oscillator means for varying the peak amplitude of said signal wave, a cathode ray tube at said remote point connected to said receiver and provided with beam-deflecting means and with a beam intensity: control electrode, first circuit means in said receiver connected to said beamdeflecting means for applying thereto anoscillationderived from the receivedsignalwave and having a peakamplitude varying with the displacement of said movable memberat the control point, limiter means connected tosaid first circuit means for deriving from said received signal Wave a control wave of substantially constant peak amplitude in step With saidoscillation, second circuit means connecting the output of said limiter means to said control electrode, and biasing means so connected to said control electrode as substantially to suppressthe beam of said tube except at peak portions of said control wave and, thereby, of said oscillation.

3. A remote-controlsystem comprising asignal transmitter at a control point, a signal receiver at a remote point, a communication path connecting said transmitter tcsaid receiver, oscillator means at the control point connected to said transmitter and having a variable output representing a signalwave, first selector means at the control point having a first movable member connected to saidoscillator means for varying the peak amplitude of said signal wave, second selector means at the control point having a second movable member connected to said oscillator means for varying the-frequency of said signal Wave, a cathode ray tube at said remote point connected to saidreceiver and provided with a beam intensity control electrode and with first and second beam-deflecting-means adapted to defiect the beam of said tube in two different directions, first circuit meansin said receiver connected to said first beam-deflecting means for applying thereto an oscillationderived from the received signal wave and having'a peak amplitude varying Withthe'displacement of said first movable member, limiter means connected to said first circuit means for deriving from said received signalwave a control wave ofsubstantially constant peak amplitude in step with saidoscillation, second circuit means-connecting the output of said limiter meansto said control electrode, broadband filter means connected to the output of said limiter means and having a sloping characteristic so as to derive from'said control Wave a wave of peak amplitude varying with frequency and, hence, with the displacement of. said second movable member, third circuit means connecting the output of said filter means to said second beamdeflecting means, andbiasing means so connected to said control electrode assubstantially-to suppressthe beam ofv said tube-except at peak pord s i t n 4. A remote-control system comprising a signal transmitter at a control point, a signal receiver at a remote point, a communication path connecting said transmitter to said receiver, oscillator means at the control point connected to said transmitter and having a variable output representing a signal Wave, selector means at the control point having a movable member connected to said oscillator means for varying the output thereof, a cathode ray tube at said remote point connected to said receiver and provided with beam-deflecting means and with a beam intensity control electrode, circuit means in said receiver connected to said beam-deflecting means for applying thereto an oscillation derived from the received signal Wave and having a peak amplitude varying with the displacement of said movable member at the control point, and threshold means in said receiver connected to said control electrode for applying thereto a train of 10 beam-brightening pulses in step with respective peak portions of said oscillation.

PHIL CUTLER.

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